There are numerous devices for delivering medicament on the market where the medicament is arranged in a container, such as a syringe, a cartridge or the like, and wherein the medicament is ejected through a delivery member, such as a needle or a nozzle, by having a movable stopper, inside the container, exert a pressure on medicament via a spring-biased drive member, which acts on the stopper.
A group of medicament delivery devices are defined as auto-injectors, wherein at least one of the steps of a delivery sequence is performed automatically, through a spring-biased mechanism, as a consequence of the user pressing a button or as a consequence of a previous mechanism reaching a certain stage. The steps that may be automatically activated are normally skin penetration by the delivery member, e.g. a needle, medicament delivery, and/or delivery member retraction.
In the case of automatic delivery of a medicament, a drive member, such as a plunger rod, often needs to be spring-biased, but prevented from moving until the appropriate moment. In some cases the user may determine when it is time to administrate the medicament. In other cases the medicament may be delivered when the needle has reached a certain depth after penetrating the skin. In the latter case, to initiate the automatic sequence, an actuator needs to be triggered by a user of the delivery device. The actuator may in some cases be button to be pressed by the user. The actuator may also be a movable element which triggers the automatic sequence as the delivery device is applied to the delivery site and moved in relation to the site.
It is also important to prevent the various components from moving in relation to each other during transport and handling of the medicament delivery device, i.e. during non-medical handling of the device. Depending on the different types of mechanisms for penetration, injection and possibly withdrawal, safety measures that do not interfere with the normal functions of the device need to be introduced. It may, for instance, be necessary to keep a movable container holder and medicament container from moving until it the device is unlocked. Such movement prevention means may be separated from activation prevention means but they may still need to be unlocked during an activation sequence when the device is to be used.
There are numerous ways of achieving a two-step activation of a delivery device. WO2015004048 discloses an example of a device wherein a needle shroud 7 is coupled to a syringe carrier 8 such that a shroud boss 7.1 engages a carrier opening 8.6 to hold the syringe carrier 8 against the force of a spring. At the same time the shroud boss 7.1 is held against a case boss 2.10 to prevent the shroud boss 7.1 from disengaging the carrier opening 8.6. In a first step the needle shroud is pressed against an injection site such that the needle shroud and the syringe carrier are retracted into the case 2. In a second step the needle shroud is further retracted into the housing, whereby the shroud boss 7.1 is freed of the case boss 2.10. The syringe carrier 8 also abuts a rear wall of the case 2, causing the shroud boss to be radially deflected out of the shroud opening 8.6 such that the syringe carrier is released for skin penetration.
The disclosed prior art is complicated in that it requires both the needle shroud and the syringe carrier to move jointly, relative to the case, in a first step. In the second step the case and the syringe carrier move jointly, relative to the needle shroud.
An aim of the present invention is to remedy the drawbacks of prior art and to provide an alternative container holder assembly, wherein the container holder is prevented from moving prior to activation. By means of the present invention, a container holder may be held relative to a housing and be released as a needle guard moves relative to the housing and relative to the container holder.